How do I handled exceptions in a join SQL Procedure

[john9]

In the SQL shown below I am joining several tables in order to compare record count totals. How do you cause SQL to generate a exception error and abnormally terminate the procedure when any one of the columns being compared do not match?
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select bal.detail_record_cnt, act.trl_policy_record_total, act.trl_agent_record_total
from commdev.comm_agent_balances_trl_stg1 bal, commdev.comm_policy_agent_trl_stg1 act,
commdev.comm_agent_activity_count agtcnt, commdev.comm_policy_activity_count polcnt,
commdev.comm_agent_balance_count balcnt

where bal.detail_record_cnt = balcnt.agent_balance_count
and act.trl_agent_record_total = agtcnt.agent_activity_count
and act.trl_policy_record_total = polcnt.policy_activity_count;

 

[carp]

DECLARE
lv_1 NUMBER;
lv_2 NUMBER;
lv_3 NUMBER;
BEGIN
select bal.detail_record_cnt,
act.trl_policy_record_total,
act.trl_agent_record_total
into lv_1, lv_2, lv_3
from commdev.comm_agent_balances_trl_stg1 bal,
commdev.comm_policy_agent_trl_stg1 act,
commdev.comm_agent_activity_count agtcnt,
commdev.comm_policy_activity_count polcnt,
commdev.comm_agent_balance_count balcnt
EXCEPTION
WHEN no_data_found THEN
RAISE_APPLICATION_ERROR(-20001, 'At Least One Column Is Different!');
END;